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Apple is awfully proud of the iPhone 5S, and is particularly excited about the revolution in smartphone security it is helping to usher in thanks to Touch ID. The biometric sensor had some privacy advocates worked up, however.

They didn’t like the thought of a scan of your fingerprint being saved on a smartphone. Could someone steal your phone, extract the image, and 3D-print an artificial thumb?

While Hollywood would probably like you to believe the answer is yes, it’s actually a resounding no. Apple has clarified that the Touch ID sensor doesn’t store any images on the iPhone 5S.

That’s not how biometric devices like the Touch ID sensor work. What you’ve seen in the movies — the red laser scanning down a thumb and rendering an exact replica on a screen — isn’t what happens when you place your thumb on the Touch ID. When you enroll a fingerprint on a biometric device, it’s fairly common for the enrollment software to show you something similar as visual feedback. It lets you see that a scan was good enough to use. What the sensor is actually recording is much different.

Instead of a high-resolution image, Touch ID is capturing specific characteristics of your thumbprint. They are converted by an algorithm into binary data and encrypted. Theoretically, there’s no way for someone to convert the 0s and 1s back into an image — even if they could break the encryption.

The rules might be different for the NSA, since it’s always possible that they negotiated some kind of back door access. Then again, they’d probably just go straight for the personal data on your iPhone 5S instead.